Thymine Dimer

Thymine dimer is also known as T-T dimer. Outside lines can cause DNA damage. The thymine in DNA molecules is formed as a dimer with a cyclobutylring, which is called thymine dimer. This change is likely to occur in the DNA strand adjacent to the thymaric acid. After the dimmer is formed, the synthesis of RNA primers stops at the dimmer, and DNA synthesis is hindered. Uv irradiation forms thymine dimers that are repaired by UvrABC (and in this way for some chemical damage). When DNA damage occurs, there is a swelling of the variant region, where the protein UvrA and UvrB bind to the denatured region, and the DNA is unchained and ATP is involved in the process. Subsequently, Uvr C proteins bind to the complex at the site of injury. The two ends of the 12 nucleotide spacing adjacent to the site of injury are cut, and the 12 nucleotide fragments of the site of injury are removed through the chain dissolution under the effect of the enzymatic hydrolysis. Subsequently, gaps are added under the effect of DNA polymerase 1, and dark repair is completed under the effect of the ligase. After the reaction, Uvr A, B and C are destroyed by protease hydrolysis. The repair is complete.